Well, you asked, and I do have an account. Why? Primarily to send/receive money from people that are multiple states away, it's considerably more convenient than the USPS.
And no, I don't 'support' the company any more than I support my local grocery store, however if I didn't use anti gun companies, I'd probably have trouble finding clothing that I like and can afford, wouldn't have an education (I'm willing to bet most of my textbooks are published by companies that might be considered anti gun) likely would have to pay more for food to find somewhere that doesn't have any anti 2a policies, and so on and so forth.
Frankly, I can't AFFORD not to use them, and even if I could, it's insane to think we can completely avoid these companies. I do what I can, where I can, but don't expect me to commit myself to undue hardship that won't serve any tangible benefit just for the sake of symbolism.